This adds the java_cpp_features GN rule to autogenerate Java String
constants representing C++ features. This refactors parts of
java_cpp_strings so java_cpp_features can share it.
This aims to address the most common syntaxes for declaring C++
features (string literal names, "brace" and "equals brace"
initialization, with & without the "base::" namespace).
Design: http://go/autogen-java-features
Bug: 1060097
Fixed: 1091031
Test: vpython build/android/gpy/java_cpp_strings_tests.py
Test: vpython build/android/gpy/java_cpp_features_tests.py
Test: tools/md_browser/md_browser.py docs/android_accessing_cpp_features_in_java.md
Change-Id: I5311f72f8837c122186148cf183f4219087df96a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412840
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812889}
